486SX with no coprocessor

Forum: Other Help Topics
Topic: 486SX with no coprocessor
started by: Bezda

Posted by Bezda on May 16 2004,12:19

I tried to install DSL on my 486SX 25MHz machine, but when I try to boot, it ends with error: "No coprocessor found and no math emulation present. Giving up." I don't know what to do... Please help me.

Posted by SaidinUnleashed on May 16 2004,19:30

that's easy,

if there is no co-processor (goes in the proc mount nets to the 486sx) DSL won't work. easy as that.

now, go toss that thing in a dumpster. when someone pulls the co-proc out, it makes em useless.

Sorry.

Posted by ripcrd6 on May 27 2004,14:44

Try a search for small linux. You have some options that are more difficult than DSL.

< http://www.superant.com/smalllinux/ > - works on 386 w/ 2 or 4MB of ram. I had a 386 that was given to me that works and could do this. Mine is also missing a math co-processor. I want to go from 4MB to 8MB of ram too. Why mess with it? Because I can!!

< http://mulinux.sunsite.dk/ > - I used this one for a while a couple of years ago. It's all floppy based. After that I found freesco, www.freesco.org, floppy based router.

Posted by S@nder.nl on May 29 2004,15:40

Maybe a strange idea, but isn't it possible to recoMpile the kernel and add Math eMulation ? I don't know, just guessing.

Posted by AndrewMSConvert on June 01 2004,09:44

Or you can give www.freeDOS.org a go

Bring back some old DOS to life :P

Posted by skaos on June 04 2004,14:52

I have compiled a kernel that should work on systems without a coprocessor - I haven't tried it on a 486sx, but it works fine on a P1-mmx. I can put it on the web if you want to try.

Posted by Bezda on June 04 2004,17:02

skaos: Yes, I would be very appreciative, if you send me your kernel. I'm newbie to Linux , so I don't know how to compile kernel. Please let me hear from you on ICQ#283244418

Posted by AwPhuch on June 04 2004,18:33

quick howto compile a kernel (easy version)

1. Get kernel image from < http://www.kernel.org/ >
2. Untar kernel image after checking md5 hash and mv/cp to /usr/src/linux
3. make menuconfig <--personal preference (make xconfig if you have x capability)
4. make dep && make bzImage && make modules && make modules_install (wait..wait...wait...wait...wait)

not much to it...but waiting for a kernel to compile on a 486sx 25mhz would take about 2 days!!!!!

Brian
AwPhuch

Posted by skaos on June 05 2004,14:07

The kernel for a 486sx is here: < http://www.ipt.ntnu.no/~knutb/div/index.html >

I'm no expert, so I thought that I just could replace vmlinuz on the boot diskette (created from boot.img), it would work. This doesn't work, so for the time beeing, the only way I can think of to install on a 486sx is to take out the disk, put it in a pc with a coprocessor, install DSL to the hard disk, replace the kernel, and put the disk back (and cross your fingers). I haven't tried this, so it may not work.

I'll try to fix it, but I'm no expert ... anybody else that knows?

Posted by Grim on June 06 2004,00:37

Quote (skaos @ June 05 2004,08:07)

That should work. Did you update lilo with the new kernel information?

Posted by AwPhuch on June 06 2004,11:46

You should be able to copy over the Kernel (using same name as one from floppy and the .img file as well) and it should work.

Why not compile a "catchall" i386 Kernel, instead of a i486 Kernel?

Brian
AwPhuch

Posted by skaos on June 07 2004,11:13

I have tried with three diskettes (both from win and linux) and it doesn't work - I get the following message:

Loading vmlinuz ..........
Boot failed: please change disks and press a key to continue

I checked the diskettes with "badblocks -svw /dev/fd0" - two of the diskettes were ok, the last had a few bad blocks.

I have tried loadlin from a dos partition and it works: download vmlinuz, miniroot.gz, loadlin.exe and boot.bat from < http://www.ipt.ntnu.no/~knutb/div/index.html > in a directory on your dos partition (e.g. c:/dsl) and run boot.bat with the DSL cd in the cd drive.

And the kernel is compiled for i386.

Posted by cbagger01 on June 07 2004,16:22

See this forum thread for a possible answer:

< http://damnsmalllinux.org/cgi-bin....knoppix >

Posted by skaos on June 09 2004,13:27

I tried cbagger01's thread-link, but still same error message.

I have tested the kernel with the "no387" boot prompt option on a 486dx with 20 MB and it works - "more /proc/cpuinfo" shows that there is no math processor (fpu). X doesn't work, maybe 20 MB isn't enough or maybe my display card is a bit "special" (Tseng ET4000w32 vesa bus). If it's lack of memory, maybe it would work with a hd-install.

I have put the files you need into an archive which you can find here: < http://www.ipt.ntnu.no/~knutb/dsl/index.html >

Bezda, if you're still around, other alternatives are Vector Linux 1.8 and Grey Cat Linux 3.0, or if you only have 8 MB, Basic Linux 3.21.

Posted by flatloop on Oct. 27 2004,14:49

I did notice that this topic died some time ago, but I was wondering if I could get some finely detailed instructions as to how to make DSL work on a machine without a MathCo.

I understand that the kernel has to be recompiled to include what I would call a "mathco emulator". I think my stumbling block is the fact that I have to re-compile the kernel, so if no-one minds, I would like to ask some n00bish questions.

Are all kernels compiled the same way, independent of which distro you are running?

Can the kernel be compiled on the running system, or does it have to be done "offline" (eg. a bootdisk, or livecd)

From my reading, I've determined that the kernel does not have to be compiled on the hardware it will run on. Is this true?

Skaos, this is for you... (or anyone that knows the answer) Your solution assumes that you are running a DOS based system as well. Is there a way to copy your kernel to the HD installed DSL without DOS intervention?

I'm sorry for all the seemingly basic questions, but I think if I understand the kernel a little better, I might not be so afraid to compile one.

Thanks in advance...

Posted by skaos on Oct. 28 2004,13:07

Quote

Are all kernels compiled the same way, independent of which distro you are running?

Yes (if I remember correctly, some time since I last did it).

Quote

Can the kernel be compiled on the running system, or does it have to be done "offline" (eg. a bootdisk, or livecd)

It can be compiled on a running system.

Quote

From my reading, I've determined that the kernel does not have to be compiled on the hardware it will run on. Is this true?

Yes.

Quote

Skaos, this is for you... (or anyone that knows the answer) Your solution assumes that you are running a DOS based system as well. Is there a way to copy your kernel to the HD installed DSL without DOS intervention?

If you boot via DOS there is no need to do this. If you want to use lilo for booting you have to copy the kernel to /boot in your Linux partition and then make sure that lilo uses this kernel (doesn't matter what it is called).

Posted by Fordi on Nov. 18 2004,21:00

If you've got a kernel that supports coprocessorless execution (and has the cloop patch), you can just substitute the kernel on the dsl 0.8.4 iso (it's "/boot/isolinux/linux24")

I would suggest starting with Knoppix on a full-powered machine and making the necessary changes to the existing kernel configuration so it'll work with coprocessor emulation, then compiling that kernel (cos it's the one DSL uses, thus best for drop-in replacement).